Process of producing sugar in crystal form.



No. 673,496. Patented May 7, 190i.

- H. GLAASSEN.

PROCESS OF PRODUCING SUGAR IN CRYSTAL FORM.

(Application filed Sept. 22, 1900.)

(No Model.) 3 Sheets-Sheet I.

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H. CLAASSEN. PROCESS OF PRODUCING SUGAR IN CRYSTAL FORM.

(Application filed. Sept; 22, 1900.) (No Model.) 3 Sheets-Sheat 3.

J I [7 17 J1 a; a s I INVENTDR WITNESSEE:

Q 44 a BY ATTORNEYS UNITE [STATES PATENT OFFIQE.

HERMANN OLAASSEN, OF DORMAGEN', GERMANY.

PROCESS OF PRODUCING SUGAR IN CRYSTAL FORM.

SPECIFICATION forming part of Letters latent No. 673,496, dated May 7,1901.

Original application filed January 4, 1900, Serial No. 301. Divided andthis application filed September 22, 1900. Serial No. 30,831- (Nospecimens.)

To all whom, it Weary concern:

Be it known that I, HERMANN CLAASSEN, a subject of the King of Prussia,Emperor of Germany, and a resident of Dormagen, Rheuish Prussia, GermanEmpire, have invented new and useful Improvements in Processes forProducing Sugar in Crystal Form from Syrups, of which the following is aspecification.

This application is a division of my application, Serial No. 301, filedJanuary 4, 1900, upon which United States Letters Patent No. 664,465,dated December 25, 1900, were issued. In that patent I have described aprocess for the production of sugar crystals out of syrup, in whichprocess indirect heatingsteam is used to produce a desiredsuperconcentration of the syrup alternating with the use of direct steamintroduced into the mass for maintaining it at a temperaturecorresponding with the vacuum for the time being. By this process theformation of crystals takes place out of the syrup itself, whereby thecrystals so produced serve as exciters for the further crystallizing outof the syrup. In some instances, however, I have found it of greatadvantage not to form the crystals directly out of the syrup by boilingto grain, but to introduce sugar crystals of suitable form into thesyrup, which will serve to initiate crystallization. By this process thesugar crystallizing out of the syrup settles down on the surface of theintroduced crystals. This method of working, in connection withalternately using indirect heating-steam and direct steam introducedinto the mass, as well as the maintaining of fixed water percentages ofthe syrup during the boiling process, will be of special advantage insuch cases where it is desired to obtain extraordinarily'large crystals.This willalso be the case whenever it becomes necessary to make sugarout of very impure syrups, as the boiling of the latter to grain canonly be accomplished by very slow boiling, and in some cases it evenbecomes altogether impossible. The crystals to be put into the syrup maybe ofwidely-different character and quality. Raw sugar or masse-cuite,first product or after products, powder-sugar or sugar-dust may be usedfor this purpose.

It should be well understood that by the excite its crystallization mustbe in a state of feeblesuperconcentration. Shouldthesyrup only beconcentrated-i. 6., should it be impossible to dissolve any more sugartherein' no crystallizing out of sugar could take place out of such asolution. On the other hand, should the syrup be highlysuperconcentrated new crystals would be formed out of such syrup. Thisformation of new crystals, however, is not desired; but the sugar whileseparating itself from the syrup should deposit on the crystalsintroduced into the solution. This is only possible when the solution isof feeble superconcentration. The superconcentration of the syrup canonly be obtained by boiling it. The required degree ofsuperconcentration depends upon the purity of the syrup and changes inaccordance with it. It will therefore vary in accordance with the degreeof the purity of the syrup. As before stated, superconcentration ismaintained to such a degree that no new crystals will be formed afterthe sugar crystals to serve as exciters of crystallization are put intothe mass, while at the same time no dissolving of these crystals canoccur. By working in the abovedescribed man ner the coefficient ofsuperconcentration of the syrup must therefore be kept above one, but atthe same time it must be kept lower than the one necessary for theformation of grain out of the syrup. If a syrup of, say, eighty tosixty-five purity is boiled to grain, the coefficient ofsuperconcentration will be 1.20 to 1.50; but by Working in accordancewith my process the coefficient of superconcentration of asyrup ofeighty to sixty-five purity will be between 1.05 and 1.20. Therefore thepercentage of water of the syrup which is to be crystallized out mustcorrespond with the coefficient of superconcentration of this processwhile drawing in the sugar crystals to be used as exciters ofcrystallization. In order to obtain and to maintain such percentage ofwater, the controlling apparatus described in my United States PatentNo. 661,756, under date of November 13, 1900, should be used.

In the accompanying drawings Ihave shown an apparatus for carrying outmy invention.

In the drawings, Figure 1 indicates a double vacuum-gage. Fig. 2represents the calculating-scale. Fig. 3 is a table containinginformation concerning the percentage of water of the syrups whileboiling before and during the addition of sugar. Fig. 3 is a table ofthe water contents of the mass after the addition of sugar. Fig. 4 is aside view of the tables shown in Figs. 3 and 3 Fig. 5 is a face View ofthe indicating-slide of the tables. Fig. 6 is a sectional elevation ofthe apparatus.

In the drawings, Fig. 1 shows a double vacuum-gage consisting of twogages h 1', communicating with the vessel 9', which communicates by atube 0 with the vacuum-pan. The vacuu m-gages are adjustable forcalibration by adjusting means h i, so that the vacunm-gages can beadjusted in accordance with the prevailing atmospheric pressure. forestated, the double vacuum-gage communicates with the vacuum-pan, whichconsists of an outer shell A, a heating apparatus 13, consisting of achamber traversed by vertical pipes by which the liquid in the lower andupperpart of the pan may circulate. The pipe 0 is for the purpose ofintroducing indirect or heating steam into the heating apparatus B. Dindicates the pipes for introducing direct steam into the vacuum-pan. Eis the stirring device rotated by the gearing F. H indicates thethermometer, and J the pipe for drawing off the ready masse-cuite, and Kis the pipe for drawing in the syrup. The vacuum-pan A is connected bypiping w and q with a small auxiliary vacuum-pan m, supplied with thepipe 01', leading to the vacuum-pump, pipe 0 for introducing juice orsyrup into pan on, heating apparatus 19, and outlet-pipe q, providedwith a valve r. Below the entranceof pipe q into the outlet '11) of thevacuum-pan A a slide-valve s is arranged, so that the pan A may beconnected to the auxiliary vacuum-pan m for drawing in into Amasse-cuite which has been boiled to grain in the pan m, which grainacts as an exciter of crystals in the masse-cuite boiled in thevacuum-pan A, or the pan A may be connected with the crystallizingapparatust by closing the valve 4" and opening the slidevalve 8 for themasse-cuite of A, mixed with the grain containing masse-cuite of m, torun into the said apparatus t. The latter is connected with a box u foradmitting a diluent of predetermined quantity in the apparatus t. r isthe centrifuging-machine for separating the crystals from themother-liquid.

The process is carried out in the vacuumpan, as hereinafter described,the structure shown in Fig. 1 being employed to give the air-pressure inthe vacuum-pan.

The structures shown in Figs. 2, 3, 3 4, and 5 are employed to aid thesugar-boiler in carrying out the process and enable him to maintain aproper degree of superconcentration at every stage of the process.

In Fig. 2 is shown a base 70, provided with As bea plurality of scales LT. The scale L indicates centimeters of vacuum, and the scale Tindicates temperatures at which Water will boil at such vacua, the twoscales beihg so correlated with each other that a single index may beemployed, cooperating with both scales, the vacuum indicated by theindex corresponding with the temperature indicated thereby, so that bysetting the index at any point in the vacuum-scale the boiling-point ofwater at that vacuum will be indicated on the temperature-scale. I havealso shown a double scale S, which slides freely upon rails 0 19, beingmovable thereon by pinion or handle q. The pini0n,which is not shown,meshes with the rack r on the side of the rail 19. The double scale Sconsists of a temperatu re-scale t, which indicates degrees oftemperature, the divisions on the scale tcorresponding in size with thedivisions on the scale T, the numerals on the scale t indicatingtemperatures which the boiling syrup has in excess of the boiling-pointof water at the same vacuo. The other scale u of the double slidingscale S shows the percentage of water contained by the syrups if theraising of boiling-point is equal to the exact opposite degrees on scale25. The sliding scale S is provided with an indicator O, stationary withrespect to the said scale when the apparatus is in use. This indicatorcooperates with the vacuum-scale and the temperature-scale T. Thesliding scale S is provided with a sliding indicator Z, which cooperateswith the scales t, u, and T.

In Fig. 3 I have shown a table in which the percentage of Watercontained in the liquid treated is given after the introduction of thesugar. In the columns 0, b o d e 9 the percentage of water of various ofthe stages of the operation are given. This table consists of anundercut or mortised board w, in which a slide yslides, This slide y isprovided with a temperature-scale and with an aperture X, so that thesaid slide may be moved along the table for a convenient reference toavoid the possibility of mistake.

In using the calculating device the double scale is moved until theindicator 0 points to that place on the vacuum-scale which correspondsto the figureindicated by the vacuummeter. Thereupon the boiling-tableis consulted and the movableindicator is adjusted to that point on thescaleu which corresponds to the percentage of water desired, whereuponthe boiling is effected at the temperature on the scale T indicated byZ. It will thus be seen that the sugar-boiler has at hand the means fordirecting the boiling of syrups or juices with the greatestexactness. Itwill also be observed that this apparatus enables me to calculate thepercentage of water of the juice or syrup at any temperature andpressure.

Table Fig. 3 which is similar in construction to the table shown in Fig.3 is used for the purpose of boiling the syrup to a condition ofsuperconcentration corresponding to its purity and also to keep itswater contents at the point necessary while "drawing in the crystalsused as exciters of crystallization.

As the sugar introduced in the form of crystals may have a lowertemperature than the contents of the vacuum-pan, provision must be madethat the temperature throughout the entire vacuum-pan is kept up to theboiling-point while sugar crystals are slowly drawn into the pan inorder to prevent any local cooling down in the apparatus. This is doneby introducing direct steam into the mass, which latter should also bestirred by mechanical means all the time While boiling.

It is not advisable, after finishing the drawing in of the exciting-crystals to increase the superconcentration of the syrup at once to thepoint required by the continuous treat ment of the syrup which is to becrystallized out and which is shown in table Fig. 3. On the contrary,the reduction of the Water percentage must proceed by slow and gradualevaporation.

After the desired percentage of water is reached according to table Fig.3 the process is continued as described in my Patent No. 664,465, datedDecember 25, 1900.

The process, improved in the above-mentioned manner, for obtaining sugarin form of crystals out of syrups will be performed in the followingway: I subject the syrup first drawn into the vacuum-pan to aconcentration corresponding to its purity according to table Fig. 3;This is done by boiling the syrup with indirect heati n g-steam-i. e.using steam in the same manner as ordinarily used for heating purposes.This steam does not enter into nor does it. come in direct contact withthe mass. When the desired point of super-concentration is attained,theadmission of indirect heating-steam is interrupted and direct steam isintroduced into the mass. By means of this steam the temperature of themass is maintained in accordance with the existing vacuum, whereby thecondition of superconcentration is not changed, while mechanicalstirring of the mass will be continued constantly. I then proceed todraw slowly into the syrup, which has been concentrated in the aforesaidmanner, the sugar crystals of any suitable form, which will serve asexciters for the syrup to be crystallized out. completing the drawing inof the sugar crystals I can shut off the direct steam and use theindirect steam, whereby the water contents of the syrup will be reducedthrough boiling. At this stage of the process I can retard the reductionof the water contents of the syrup by slowly drawing in additionalsyrup. The process of concentration while temporarily shutting off theindirect heating-steam and introducing direct steam After into the massis continued until the percentage of water reaches the point shown intable Fig. 3 respecting the purity of the syrup. Thereafter the boilingprocess is continued as described in my Patent No. 664,465. After theboiling and concentrating process is finished and the vacuum-pan isfilled with masse-cuite this mass when cooling down will show suchviscosity that its further crystallizing out will prove diflicult. Inorder to reduce its viscosity, I treat this masse-cuite after it islowered into suitable vessels by continuously or periodically addingwater or molasses to it. This introduction of Water or molasses willdiminish the viscosity of the mass. It should, however, be limited tosuch an extent that the superconcentration of the mother-syrup is notcompletely neutralized, but only to a certain degree, as it may happenthat by adding water a solution of the sugar crystals already separatedtakes place. This further crystallization of the masse-cuite in adiluted state may take place either while the mass is in motion or whenit is at rest.

What I claim, and desire to secure by Letters Patent, is- 4 Theherein-described process of producing sugar which consists in producinga concentration of the juice or syrup in 'vacuo in .ac-' cordance withits purityby means of indirect heating-steam, interrupting the flow ofsuch steam and thereupon introducing steam directly into the mass forthe purpose of maintaining a temperature in accordance with the vacuumWithout changing the degree of concentration of the mass, thenintroducing sugar into the mass to serve as an eXciter ofcrystallization, then shutting off the steam which is being directlyintroduced into the mass, and drawing in fresh syrup, continuing thealternate use of indirect steam for producing concentration as requiredby the condition of the boiling process for the time being and ofdirectly-"introduced steam for maintaining the temperature withoutchanging the degree of concentration, meanwhile continually stirring themass by means other than the steam and thereupon treating the mass forthe purpose of further crystallizing out, reducingits viscosity byadding a diluent in conformity with the lowering of the temperature andseparating the sugar so produced from the molasses, substantially asspecified.

In testimony that I claim the foregoing as my invention I have signed myname, in presence of two witnesses, this 10th day of September, 1900.

HERMANN- oLAAssEN.

Witnesses WILLIAM EssENwEIN, LUDWIG HIRT.

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